• Transactions on Electrical and Electronic Materials
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• v.16 no.4
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• pp.169-172
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• 2015

Although, there are several research studies on the engineering of the graphene layers using different etching techniques, there is not any comprehensive study on the effects of using different etching masks in the reactive ion etching (RIE) method on the quality and uniformity of the etched graphene films. This study investigated the effects of using polystyrene and conventional photolithography resist as a etching mask on the engineering of the number of graphene layers, using RIE. The effects were studied using Raman spectroscopy. This analysis indicated that the photo-resist mask is better than the polystyrene mask because of its lower post processing effects on the graphene surface during the RIE process. A single layer graphene was achieved from a bi-layer graphene after 3 s of the RIE process using oxygen plasma, and the bi-layer graphene was successfully etched after 6 s of the RIE process. The bilayer etching time was significantly smaller than reported values for graphene flakes in previous research.

• Journal of the Semiconductor & Display Technology
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• v.6 no.3
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• pp.61-64
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• 2007

V-groove device was fabricated for precision coupling of planar optical splitter and optical fibers. V-groove was made through select wet etching of Si wafer by using KOH solution. Etching rate and surface roughness were checked, changing KOH composition(10, 20, 30, 33, 40 wt.%) and etching temperature (50, 60, 70, $80^{\circ}C$) to fabricate V-groove device effectively. Etching rate was the fastest as $1.84\;{\mu}m/min$ in case of etching by 20 wt.% KOH on $80^{\circ}C$, surface roughness was the best in case of etching by 33 wt. % KOH on $80^{\circ}C$.

• Journal of the Semiconductor & Display Technology
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• v.2 no.4
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• pp.19-22
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• 2003

In this paper, Si anisotropic etching characteristics of tetramethylammonium hydroxide (TMAH)/ammonium persulfate (AP) solutions were investigated to realize the optimum structure of a diaphragm for the piezoresistive pressure sensor application. Due to its low toxicity and its high compatibility with the CMOS processing, TMAH was used as Si anisotropic etchants. The variations of Si etch rate on the etching temperature, TMAH concentration, and etching time were obtained. With increasing the etching temperature and decreasing TMAH concentrations, the Si etch rate is increased while a significant non-uniformity exists on the etched surface because of formation of hillocks on the <100> surface. With the addition of AP to TMAH solution, the Si etch rate is increased and an improvement in flatness on the etching front is observed. The Si etch rate is also maximized with increasing the number of addition of AP to TMAH solution per one hour. The Si square diaphragms of 20$\mu\textrm{m}$ thickness and 100-400 $\mu\textrm{m}$ one-side length were fabricated successfully by adding AP of (5/6)g to 800 ml TMAH solution every 10 minutes.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.8
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• pp.12-16
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• 2002

It is confirmed that the ITO(Indium Tin Oxide) thin films can be etched by low-temperature plasma at atmospheric pressure. The etching happened deepest at a hydrogen flow rate of 4 sccm, and the etch rate was 120 /min. The etching speed corresponded to the H$\alpha$* emission intensity The etching mechanism of the ITO thin films is as follows; thin films were reduced by H$\alpha$*, and the metal compound residues were detached from the substrate by reacting on the CH* The etching was started after etching time of initial 50 sec and above the threshold temperature of 145$^{\circ}C$. The activation energy of 0.16 eV(3.75 Kcal/mole) was obtained from the Arrehenius plots.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.162-163
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• 2007

The dry etching of Si was investigated using direct dc biasing to the Si substrate. The TCP type etching system with a feed-through for applying a dc bias was used in the etching. The applied dc bias and ICP power was varied to examine the effect on the etching at the fixed chamber pressure and $SF_6$ flow rate of 10 mTorr and 10 sccm during. When the plasma was generated at ICP power of 100 W, the etch rate of Si was increased with the bias for the biased samples. However, the etching of Si for the non-biased sample was enhanced for the increased ICP power.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.3-4
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• 2005

The Pseudo-MOSFET measurements technique has been used for the electrical characterization of the nano SOL Silicon islands for the Pseudo-MOS measurements were fabricated by selective etching of surface silicon film with dry or wet etching to examine the effects of the etching process on the device properties. The characteristics of the Pseudo-MOS was not changed greatly in the case of thick SOI film which was 205 nm. However the characteristics of the device was dependent on etching process in the case of less than 100 nm thick SOI film. The sub 100nm SOI was obtained by thinning the silicon film of standard thick SOI. The thickness of SOI film was varied from 88 nm to 44 nm by chemical etching. The etching process effects on the properties of pseudo-MOSFET characteristics, such as mobility, turn-on voltage, and drain current transient. The etching process dependency is greater in the thinner SOI and related to original SOI wafer quality.

• Textile Coloration and Finishing
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• v.9 no.6
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• pp.10-17
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• 1997

In order to improve the anti-static property of several hydrophobic fibers by sputter etching, polyester, polypropylene and poly(p-phenylene sulfide) have been etched by sputtering in the presence of argon gas and the resulting anti-static property investigated by half time decay, the time of water permeation, weight loss rate and scanning electron microscope(SEM). The temporary change and durability of anti-static property of samples treated with sputter etching were evaluated. The results were as follows; 1) Half time decay of samples treated with sputter etching were decreased about 18~38%. According to increasing sputter etching time, half time decay is decreased. 2) The wettability and weight loss rate of treated samples were increased remarkably. According to the SEM photographs, many microcraters on the substrate surface by the sputter etching were observed. 3) Although the washing treatment and the time elapsed after treatment are allowed longer, the variation of half time decay hardly can find.

• Journal of Magnetics
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• v.12 no.2
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• pp.81-83
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• 2007

Etching of NiFe films covered with an organic photo-resist or Ti was successfully performed by an inductively coupled plasma-reactive ion etching (ICP-RIE) system using $CHF_3/O_2/NH_3$ discharges exchanging $CHF_3$ for $CH_4$ gas gradually. Experimental results showed that the organic photo-resist mask can be applied to the NiFe etching. In the case of the Ti metal mask, it was found that the etching-selectivity Ti against NiFe was significantly varied from 7.3 to ${\sim}0$ by changing $CHF_3/CH_4/O_2/NH_3$ to $CH_4/O_2/NH_3$ discharges used in the ICP-RIE system. These results show that the present RIE of NiFe was dominated by a chemical reaction rather than a physical sputtering.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.4
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• pp.77-82
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• 2022

During etching process of PCB, the electroplated copper line and seed layer copper have different etching rates and it caused the over etching of copper line as well as undercut of lines. In this research, the effects of etchants composition on copper etching characteristics were investigated. The optimum concentration of hydrogen peroxide and sulfuric acid of etchants were obtained using polarization and OCV (open circuit voltage) analysis for both rolled copper and electroplated copper. The inhibiting effects of different inhibitors were investigated using OCV and ZRA (zero resistance ammeter) analysis. The galvanic current between electroplated copper and seed layer copper were measured using ZRA method. Inhibitors for least galvanic current could be chosen based on galvanic coupling in ZRA analysis.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.4
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• pp.514-521
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• 2009

The aim of this study was to evaluate the bonding ability of two self etch systems to human primary and permanent enamel and the effect of additional acid etching time. Exfoliated, caries free human primary molar(n=65) and permanent molar extracted (n=65) were used. prepared enamel specimens were randomly divided into 2 test groups and a control group. The control group(n=10) were treated with 35% phosphoric acid gel and Scotchbond Multi-purpose adhesive. Experimental groups(self-etching systems) were subdivided into 6 groups(each n=10) according to additional etching time(0s, 5s, 10s, 15s, 20s, 30s). The result were as follows : 1) The shear bond strengths of the self-etching adhesives(Clearfil SE Bond, Adper Prompt L-pop) without additional etching were lower than control group(Scotch Bond Multipurpose). 2) Between the same self-etch adhesive groups, additional etched groups showed higher shear bond strength 3) There was no significant difference between primary and permanent enamel. In conclusion, bond strength of self-etch adhesives to enamel could be increased with additional etching.